This application requests the purchase of a Matrix-Assisted Laser Desorption Ionization (MALDI)-TOF-TOF (Time-of-Flight) mass spectrometry instrument for multi-investigator use in the Mass Spectrometry Laboratory (MSL) at the University of Illinois at Urbana- Champaign. The MSL serves a large number of departments at the University of Illinois and also receives many samples from outside. The requested instrument has greatly improved mass accuracy compared to our current MALDI instrument, and can deliver routine MS-MS data unlike our current instrument. Access to the requested state-of-the- art technology would enable many critical experiments in NIH-funded laboratories at the University of Illinois that cannot be performed at present. In particular, it will greatly aid the investigation of the biosynthesis of peptide antibiotics, the structural elucidation of cyclic antimicrobial peptides discovered from genome databases, the development of dendrimers as drug delivery vehicles, the development of important new sensors for volatile organic compounds, and the understanding of nucleic acid catalysis and molecular recognition. In addition, the requested instrument will be used to better understand metalloenzymes that are key to human health as well as to elucidate glycan biosynthetic pathways. PUBLIC HEALTH RELEVANCE: This application requests funds to purchase a state-of-the-art instrument that can accurately determine the weight of large biomolecules. In addition, the instrument can fragment the molecules and analyze the fragments, thereby providing further information that is key for biomedical scientists. The requested shared instrument will provide data for more than 100 scientists at the University of Illinois.